Up on the Columbia River near Woodland, Wash., Howard Warrus recently caught a fish that he couldn’t identify in his crawfish trap.

“He reported the first one to Washington Fish and Game,” says Bruce Holt. “But they just said that it was probably someone’s aquarium fish and never got back to him.”

Warrus then caught six more, all from the same location.

Holt, communications director at G.Loomis and an angler who loves the Columbia, is concerned. He asks, “If he’s taken seven from a very small area, how many more are there in the river?”

I am worried too. We’ve seen what exotics can do, courtesy of zebra mussels and Asian carp, just to name a few.

I’ve done a little research and I believe that this invader is the Oriental weatherfsh, also known as the weather loach or Japanese weatherfish. If I'm wrong in my identification, the fact remains that this fish is one more exotic threatening our waterways.

Mystery fsh has six barbels, just like weatherfish.

Many of the invaders now causing problems in our aquatic systems were introduced by ballast water from ocean-going ships or commercial fish farmers.

But the aquarium trade --- and irresponsible pet owners --- deserves most of the credit for this one, if it is the weatherfish.

The weatherfish appears to be a fairly innocuous bottom-dweller that grows to about 10 inches. So why should we be concerned?

“Impact of Introduction: It may reduce populations of aquatic insects important as food to native fishes.”

And then there are the unforeseen consequences that we are beginning to experience more and more:

Flying silver carp that injure boaters and anglers, as well as crowd out native species.

Thousands of loons and other fish-eating birds dead from botulism, likely contracted by eating round gobies, an exotic species that absorbed the toxin from consuming zebra mussels, another exotic.

Eagles dead from avian vacuolar myelinopathy because of hydrilla. The raptors eat coots and other birds that feed on the exotic plant, which harbors an alga containing neurotoxins. Since its discovery in 1995, AVM has killed hundreds of eagles across the Southeast.

And the weatherfish and hundreds of other exotics now infesting our fisheries? We’ll just have to wait and see.